Rotary pump



Oct. 25, 1938. E. w. TILTON 2,134,219

ROTARY PUMP Filed Dec. 18, 1936 2 Sheets-Sheet 1 E. w. TILTON 2,134,219

ROTARY PUMP Filed Dec. 1a, 1936 2 Sheets-Sheet 2 i6? 40% 9 o-h r Patented ot. 25,*193s v 2,134,219

UNITED STATES PATENT ROTARY PUMP Edward W. Tilton, Oshkosh, Wis., assignor of one-half to Harry R. Kay," Winnetka, Ill.

- Application December 18, 1936, Serial No. 116,457

' 2 Claims. (01. 103-144) My invention relates to rotary pumps and parportions of these passageways being defined by ticularly to rotary pumps of the impeller or vane suitable hollow bosses or projections 9 and H type, such as are used for pumping oil, water, cast integrally with the housing. The outer ends milk, pulp, and other liquids. of these projections may be conveniently thread- 5. Stated generally, the principal object of the ed"for connection to pipes or the like, as at l2. 5..

present inventionisto provide an improved rotary To give increased rigidity to the housing, cen--- pump of the impeller or vane type which shall trally disposed external ribs l3 are cast integralbe more eificient in operation, less expensive to ly therewith, the ribs I3 extending between the construct and manufacture, and easier to repair, feet 3 and the inlet and outlet passageway de- 10 clean, and service than any of the pumps herefining projections 9 and H. l tofore known to the art. Somewhat more spe- The bore l5 of the housing I is accurately cifically, it is an object of the present invention machined to a cylindrical form, and the two ends to provide an improved rotor structure for use of the housing I6 and I1 are machined flat in in pumps of the subject type; to provide an implanes substantially perpendicular to the axis of proved impeller assemblage for use in pumps of the bore l5. Spaced holes I9 are provided in the 15 the subject type; and to provide an improved side walls of the housing for. receiving tie bolts seal and bearing structure for use in pumps of which serve to hold the stationary parts of the subject type. the pump in the assembled position.

These and other objects of the invention, and The housing is closed at either end thereof 20 the preferred method of accomplishing the same by: an end plate 2|, preferably of cast metal. 20

will bem'ade more apparent by reference to'the Each of the end plates 2|, as is particularly illusfollowing description taken in conjunction with trated in Figures 2 and 3, includes an inwardly the attached drawings, whereinprojecting, hollow boss 23, the outer surface Figure 1 is a sectional view through a rotary of which is accurately machined to a cylindrical 25 pump embodying the features'of the present inform. Each of the bosses 23 is provided with an 25 vent'ion; inner bore 26 eccentrically disposed with respect Figure 2 is a sectional view on the line 22 of I to the outer surface 25 thereof, and with a cylin- Figure 1; drical opening 21 for receiving the shaft 29 form- Figure 3 is an exploded perspective; view showinga part of the pump rotor. 30 ing the rotor, the impeller assemblages, and cer- A somewhat similar hollow boss 3| projects 30 tain other of the structural features of the pump outwardly from the outer surface of eachof the illustrated in Figures land 2; end plates 2|, the bosses 3| having a cylindrical Figure 4 is a perspective view of one of the bore 33 for receiving the bearing and the gland -impeller assemblages; I seal, which will be described indetail later. The Figure 5 is an elevational view, partially in outer edge of each of the end plates 2| is re- '35 section, of one of the impeller assemblages; cessed to form a-fiange 34 for engaging the end Figure 6 is a sectional view showing the feasurfaces l6 and I! of the housing I, and suitable tures of one of the roller members which serve holes 35 are providedin the flange for receiving to connect'the impeller blades to the rotor proper; the tie bolts 20 which extend through the holes 40 .Figure 7 is an end elevational View of thisin the housing. I 40 I roller support, the view being taken on the gen- It will be seen that when the end plates 2| eral line of Figure 6; are fastened-in positionupon the housing the Figure 8 is a. sectional view on the line 88 of space enclosed thereby will be substantially cylin- Figure 6; and a drical in form.- The pump rotor-is adapted to Figure 9 is a fragmentary, perspective view move within this space and includes a generally 45 of one of the combined bearing and seal struccyl dr cal b y m p -fi ed and tures forming a part of the pump illustrated I keyed to the rotor shaft 29 which extendsthrough particularly in Figures 1 and 2. theialigned openings 21 in the end plates 2|. At

The-pump illustrated in the drawings includes either end thereof the rotor body 31 isundera generally cylindrical housing preferably of cut by an "annular recess 39 for receiving the 50 cast metal. Suitable. feet 3 for attaching the bearing portions of the impeller assemblages 4| pump to the supporting structure therefor are which are mounted upon theinwardly projecting cast integrally with this housing. Intake and bosses 23 forming a part of the end plates 2|. discharge passageways 5 and respectively, are The rotor body is provided along the periphery provided in the walls of the housing I, the outer thereoi with a plurality of longitudinally extend ceiving the impellers and their supports. These slots 43 are open along the periphery of the pump rotor 31 and connect with the annular recesses 39 at either end thereof. In the pump -illustrated in the drawings, the rotor body 31 is provided with four of the slots 43. It will be understood that any number of such slots as is indicated by the design of the pump may be used.

The end surfaces 45 of the rotor body 3'! are machined flat in planes substantially perpendicular to the axis of rotation of the rotor, and the longitudinal width of the rotor is made slightly lessthan the width of the space enclosed between the end plates, i. e., suficient clearance being provided to accomplish a good running ht between the end plates 2i and the ends of the rotor body. For pumps of moderate capacity, a clearance of two-thousandths of an inch will generally be found satisfactory for this purpose. If desired, shims may be used intermediate the end surfaces it and ii of the housing and the adjacent surfaces of the end plate flanges 3% for permitting adjustment of the width of the enclosed space during the operative life of the pump.

The impeller assemblages il forming a part of the pump of my invention are illustrated particularly in Figures 3, 4, and 5, and as will be seen from inspection of those figures, each of these assemblages includes a pair of impeller members ll and it which are normally assem bled in cooperative unitary relationship. For convenience, I have designated one of these impeller members (the member fill) as the male member and the other (the member 68) as the female member. Both types of members are provided with an impeller blade as generally rectangular in cross section.

Each of the impeller members also includes an annularly shaped hub or bearing portion. The hub portion of each of the male members l? is provided with a cylindrical bore 52 adapted to be journaled upon the outer surface 25 of one of the inwardly projecting bosses 23 forming a part of each of the end plates 29. The outer surface of the bearing portion of each of the .male impeller members 41 is provided with an.

annular recess 53 which is adapted to engage a suitable flange forming a part of the hub portion of the cooperating female member 48 with a bearing fit. By virtue of this arrangement, the two impeller members may be assembled into the unitary relatiozfship, shown particularly in Figures 4 and 5, and each of these units can then be journaled upon one of the inwardly projecting bosses 23 forming a part of each of the end plates 2 I, as illustrated in Figure 2. It will be seen that this arrangement permits the maximum possible bearing surface for each of the impeller assemblages, which necessarily rotate at the same speed as the pump rotor, and yet at the same time it permits relative movement about the axis of rotation of the unit as a whole between the male and female impeller members making up each of the impeller assemblages. This constructional arrangement of the impeller units is one of the. important features of the present invention.

The impeller blades 49 are driven by .the rotor, and for mechanically interconnecting the rotor with the impeller blades, I utilize slotted, cylindrical rollers 5|, the features of which are illustrated in Figures 6, 7, and 8. One of the rollers Si is positioned within each of the cying, regularly spaced, cylindrical slots 43 for relindrical slots 43 in the rotor, and the engaging surfaces of the slots and the rollers are machined to a bearing fit. The impeller blade 49 forming a part of each of the impeller members is adapted to be disposed within a longitudinal rectangular slot 55 formed in each of the blade supporting rollers 5!. To secure the best mechanical advantage, it is desirable that this slot 55 shall have a depth greater than one-half the diameter of the roller, and to minimize the width of the pump, one end of each of the rollers 5| is providedwith a transversely extending slot 58 which aligns with the annular recess 39 in the rotor body 31! to receive the right angle portion of the impeller extending between the blade and the hub portion thereof.

This arrangement permits the width of the entire rotor, including the cooperating impeller assemblages, to be kept the same as the width of the impeller blades, thereby simplifying the problem of securing a good seal within the pump, and also materially aiding in reducing the space occupied by the pump.

I prefer to utilize roller hearings in conjunction with the pump of my invention, but it is to be understood that other types of bearings may be successfully employed. It is, of course, desirable that the bearings shall accurately position the rotor within the housing and shall be of a low friction type. The bearing and seal assemblage illustrated particularly in Figures 2 and 9 is intended for use with a roller bearing. As will be seen by reference to those figures, the bore formed in. each of the end plates 2i is partially closed at its inner end by an annular member bl which defines a suitable retaining surface for a gasket, and a gasket 58 of the conventional trapezoidal cross section type is placed against the outer surface of this member during the assembling of the pump so as to surround the rotor shaft 29.

An annular gasket retaining ring 5% of suitable dimensions is next introduced into each of the bores 33. This ring is followed by a roller bearing assemblage 60 of the conventional type, the outer race of which is adapted to abut against the gasket retaining ring. Preferably, the gasket retaining ring is recessed, as at 6!, to positively prevent any interference with the movable race of the bearing. The next element in the bearing and seal assemblage is a combined bearing and lubrication retainer 62. This member, as is shown particularly in Figure 9, is generally cylindrical in its outer dimensions and is provided with an annular recess 63 machined in the inner surface thereof for providing a lubrica-.

tion well. Lubricant is admitted into this recess through a suitable opening 54 formed in the upper portion thereof, and the proper positioning of the retainer member 62 is assured during the assembling operation by means of a pin 65 which is adapted to engage a suitable slot formed in the wall of the adjacent outwardly projecting boss II.

After the gasket 58, the gasket retaining ring 59, the bearing 60, and the bearing and lubricant retainer 82, have been placed in position within each of the bores 33, a suitable retaining nut 61 is screwed in position so as to hold the several elements in place and to tighten the gland seal.

' It will be seen that the number of structural features utilized in making up each of the bearing and seal assemblages is reduced to the barest minimum, and that substantially all of the elements are called upon to perform more than one function, the outer race portion of the bearingBIJ, for example, serving to transmit the stress induced by the retaining nut 61 to the gasket retaining ring 59, and the bearing retainer 62 also serving as a lubricant retainer. The entire assemblage is a simple and highly efficientarrangement, and not only serves to give a good seal between the shaft and the interior of the pump, but in addition constitutes a seal which is particularly free from any possibility of contamination, this feature being of great importance when the pump is used for handling milk or like liquids. Further, this arrangement permits the pump to be easily disassembled, as for cleaning.

During operation of the pump, power is applied to the rotor shaft 29 from any suitable source. Due to the eccentricity of the axes of rotation of the impeller assemblages and the rotor, the impeller blades 49 project from the surface of the rotor at all times except when they are passing across the seal point 69 at the upper portion of the pump housing. The amount of this projection varies from zero or less at this upper or seal point to a maximum at the bottom of the pump casing. The bore l5 of the housing I is concentric with the axis of rotation of the impeller assemblages 4|, and hence a very close fit may be maintained between the impeller blades 49 and the inner surface of the bore at all times during operation of the pump. This makes for high heads and high pumping efliciency. At the same time, the retractable feature of the blades assures a complete cutting 01f of the inlet and outlet sides of the pump at the seal point 69.

It is apparent that there is substantial relative movement between the impeller blades 49 and the supporting rollers 51 therefor during operation of the pump. Because of this, it. is desirable that the spaces beneath the impeller blades shall be connected in order to minimize any possibility of excessive friction due to unequal pressure distribution.

' drawings, this interconnection is accomplished by four passageways 1| (Figure 1). The outer portion of each of the passageways H is preferably formed by a suitable drilling in one of the roller members 5|, and the inner portion of each of the passageways H constitutes a connecting drilling which extends through the rotor body 3! and the shaft 29. The drillings through the shaft preferably intersect and connect with each other so as to attain the best possible equalization of pressure during the operation of the pump.

It will be also apparent that there is a certain amount of relative angular movement between the impeller blades 49 and the rotor body 31 during the operation of the pump. It is for this reason that the roller membersjl engage the slots 43 within the rotor body with a bearing fit, and that the impeller blades 49 engage the slots 55 within the rollers with a bearing fit.

In connection with the operation of the pump of my invention, I have found that the positioning and form of the inlet andcutletports 5 and I is of considerable importance. Particularly, I

have discovered that if the ports are extended along the bore of the housing I so that the actual working surface of the bore of the pump subtends an angle no greater than the angle between two adjacent impeller blades, substantial improvement of performance will result. This is accomplished in the pump illustrated in the drawings by the provision of a rectangularly shaped slot 12 formed in the side walls of the housing, which slot is extended down to a point In the pump illustrated in' the within 45 of the horizontal, as indicated at 13. The width of the slots, 12, as is shown in Figure 2,

slots 12, the actual pumping or working portion of the pump is confined to the space enclosed by two of the impeller blades. Actual tests have shown that this assures much more satisfactory and more reliable operation than has ever been accomplished in any of the prior art devices. It also permits the pump to be used for pumping liquids which contain rather large amounts of solid material, such as grit, metallic oxides orscale, machinings, and the like. The pump is completely reversible, as will be apparent from inspection of the drawings.

From the foregoing, it will be seen that I have disclosed the features. of an improved form of impeller pump which operates much more efficiently and much more satisfactorily than any of the pumps heretofore developed. This improved operation is brought about, to a considerable extent, by virtue. of the novel arrangement of the impeller assemblages, which assures a large bearing surface for each of the impeller assemblages as a whole while at the same time pre venting any undue increase in the dimensions of the pump.

The pump of my invention is an exceedingly compact structure, and there is substantially no waste space whatsoever withinthe pump housing. This means that no liquid is retained within the pump for any material interval of time, which is of great advantage from a sanitary viewpoint when pumping perishable liquids such as milk, and of great advantage from the viewpoint is purposely made substantially less than the of preventing clogging when pumping liquids containing solid material. The novel structural arrangement-of my pump permits ready disassembling thereof, thus particularly adapting it for use in pumping milk or other food products and for the pumping of pulp solutions which have a notorious tendency to clog pumps of all types. The improved pump of my invention secures a much more positive and more accurate control over the movement of the impeller blades than was heretofore believed possible of attainment, and this control is accomplished with a minimum of frictional effort. I have disclosed a novel arrangement for the ports. of the pump of the subjecttype, which arrangement contributes materially to the improved operation of the pump of my invention, and I have also dissonable construction consistent with the state ofv the art. g

I claim the following as my invention:

1. A rotary pump comprising a shaft, 8. body member supported on said shaft and having at each end thereof an annular recess arranged concentrically to the axis of the shaft, the outer portion of said member. being provided with a plurality of cylindrical slots, said slots being open along the peripheral surface of said member, a

cylindrical roller member disposed in each slot, each roller being provided with a longitudinal slot, a casing for said body member, a plate for closing each end of the casing, each plate being provided with an inwardly projecting boss positioned coaxially with respect to the axis of the casing, each boss having a circular opening therein positioned eccentric with respect to the axis of the'casing, an impeller assemblage comprising a pair of impeller members respectively supported upon each boss for rotation about said axis, each pair comprising a male impeller member and a female impeller member, each impeller member comprising an impeller blade connected to an annular hub, the annular hub of each male member having a cylindrical bore adapted to engage over a respective boss with a journal fit, the hub of each female member fitting over the hub of a respective male member, said shaft being supported within the circular openings formed in said bosses, a pair of impeller members being positioned within each annular recess, each impeller blade being positioned within a respective longitudinal slot formed in a roller member and extending through a registering peripheral opening in an associated cylindrical slot.

2. A rotary pump comprising a shaft, a body member supported on said shaft and having at each end thereof an annular recess arranged concentrically to the axis of the shaft, the outer portion of said member being provided with a plurality of cylindrical slots, said slots being open along the peripheral surface of said member-and having lateral openings communicating at each end of the slot respectively with an annular recessQa cylindrical roller member disposed in each slot and having at one end thereof a transverse slot registering with a respective lateral opening, each roller being provided with a longitudinal slot intersecting said transverse slot, the length of each roller being substantially equal to the length of said body member, a casing for said body member, a plate for closing each end of the casing, each plate being provided with an inwardly projecting boss positioned coaxially with respect to the axis of the casing, each boss having a circular opening therein positioned eccentric with respect to the axis of the casing, an impeller assemblage comprising a pair of impeller members respectively supported upon each boss for rotation about said axis, each pair comprising a male impeller member and a female impeller member, each impeller member comprising an impeller blade connected to an annular hub; the annular hub of each male member having a cylindrical bore adapted to engage over a respective boss with a journal fit, the hub of each female member fitting over the hub of a respective male member, said shaft being supported within the circular openings formed in said bosses, a pair of impeller members being positioned within each annular recess, each impeller blade being positioned within a respective longitudinal slot formed in a roller member and extending through a registering peripheral opening in an associated cylindrical slot, each blade being connected to its associated hub by a radial portion which is positioned within a respective transverse slot formed in the roller member which engages said blade.

EDWARD W. 'I'ILTON. 

